This invention relates to seismic exploration and more particularly to a method for the enhancement of the signal-to-noise ratio of recorded seismic data in order to make possible the production of a seismic section in which subsurface anomalies are more readily discernible to an interpreter.
In seismic exploration, seismic energy is generated at a shotpoint at or near the surface of the earth, is reflected from subsurface interfaces between layers of the earth, and is received by a spread of geophones on the surface of the earth. The geophone signals are conventionally gathered and recorded in the form of a suite of common-depth-point (CDP) seismic traces. From these recorded CDP seismic traces the subsurface interval velocities can be determined. Such a CDP data gathering and recording technique and a continuous velocity determination technique are disclosed in U.S. Pat. No. 3,651,451 to William H. Ruehle. An accurate velocity determination is quite important in the interpretation of the nature and extent of the subsurface layering. One of the problems encountered in such velocity determination is that incoherent noise signals are also recorded on the seismic traces along with the primary reflection signals. The method of the present invention is particularly useful in enhancing the strength of the primary reflection signals on the seismic traces in the presence of such incoherent noise signals prior to the conventional CDP data gathering operation and the processing of the CDP seismic traces by means of conventional velocity determination techniques.